ALLELOPATHY IN ACACIA MANGIUM WILLD AS A STRATEGY FOR ACQUIRE SUCCESS IN NEW ENVIRONMENTS AND POTENTIAL USE IN CONTROLLING OTHER INVASIVE SPECIES

Biological invasion is currently one of the main causes of biodiversity loss and difficult protection and recovery actions of ecosystems. Despite being an emerging area in plant ecology, few studies investigate which are the mechanisms used by alien species that make them successful in new habitats, like the release of secondary metabolism compounds that will act on development and growth of others. In Brazil, Acacia mangium Willd threat the biodiversity even in protected areas. Thus, the aim of this work was evaluated the allelopathic effect of A. mangium Willd leave extract over L. sativa , L. leucocephala and U. brizantha seeds. Leaves were collected from Parque Estadual de Itaúnas, ES, Brazil, macerated in ethyl alcohol for five days and submitted to rotatory evaporation. Metabolites classes were identified by phytochemical tests. For allelopathic bioassay, seeds of each plant tested were treated with water or one of four concentration of the extract (1, 5, 10 and 50mg/mL). Phytochemicals tests indicated the presence of triterpenos, saponins and tanins. As the allelopathic potential, the extract not only reduced germination of L. sativa in 5 and 10mg/mL but also affected the germination speed index, germination mean speed, radicular length and radicles length speed index. 50mg/mL took the full inhibition of germination. The invasive species L. leucocephala and U. brizantha also were affected by extract, although U. brizantha has been more sensitive to allelochemicals; this open a possibility of using an invasive species to control others and demonstrate the resistance of L. leucocephala even under adverse conditions. for 11 days or less, In this work, this fact occurred in days. The results show that Willd since, L. leucocephala, the GSI all although there has been significant change in the GMT and GMS parameters. The radicles also were affected by the extract more than L. leucocephala 5